BSC API: Don't treat a RRLP message as NOTICE event

While generally we should log troly unknown RR messages, we can simply
pass along RRLP messages (which aren't unknown!)

In real networks, the RRLP would probably not end up at the MSC, but
well, sometimes we don't care what real/classic networks do.

openbsc/src/libbsc/bsc_api.c

@@ -577,6 +577,12 @@ static void dispatch_dtap(struct gsm_subscriber_connection *conn,
 		case GSM48_MT_RR_CLSM_CHG:
 			handle_classmark_chg(conn, msg);
 			break;
+		case GSM48_MT_RR_APP_INFO:
+			/* Passing RR APP INFO to MSC, not quite
+			 * according to spec */
+			if (api->dtap)
+				api->dtap(conn, link_id, msg);
+			break;
 		default:
 			/* Normally, a MSC should never receive RR
 			 * messages, but we'd rather forward what we